An acronym for International Cock Blocking Association
It can be used to describe all the people in the world, who really cock block, or just random people out of nowhere who unexpectedly cock block with you and you significant other. It's an association as well because they all do the same thing: cock block.
Also, since calling someone out to be a cock blocker is too forward or you just don't want to say it out aloud, it can be used in code.
Roy: "Dude so what happened last night?"
Mike: "Nah Dude, We went to the movies last night, and her friend from school was just talking to her all the time, I thought she had a boyfriend, so it would be cool, but it turns out she was an undercover ICBA Agent"